Field of the Invention
The present invention relates to an image processing device, an image processing system and a non-transitory readable recording medium. One or more embodiments of the present invention more specifically relate to a technique to enhance power-saving effect at the image processing device that maintains a connection with a server.
Description of the Background Art
Image processing devices such as MFPs (Multi-Function Peripherals) are capable of executing jobs by working together with a server installed on a cloud on Internet. The image processing device accesses the server on Internet from a local environment, for example, thereby storing image data generated by a scan job or executing a job such as a print job by obtaining the image data stored in the server.
In the local environment where the image processing device is installed, it is general to build a firewall in a view of security. In order to send the print job from the server to the image processing device as the image processing device is not accessing the server, it is required to develop an environment that enables the server on Internet to communicate with the image processing device over the firewall.
It is conventionally introduced to install a dedicated gateway for communication with the server on Internet in the local environment to develop the above-described environment. This known technique is introduced for example in Japanese Patent Application Laid-Open No. JP 2015-115831 A. According to the known gateway, it establishes a constant connection using XMPP (eXtensible Messaging and Presence Protocol) with the server on Internet when it is powered on, for example, thereby establishing a path that allows the server to communicate with the image processing device in the local environment over the firewall. Hence, even when the image processing device is not accessing the server, the server on Internet communicates by a tunnel by using the path established between the gateway and the server, thereby sending information such as the print job to the image processing device in the local environment.
The image processing device having a function of the above-described gateway function has been provided recently. The image processing device is configured to establish the connection with the server on Internet and communicate with the server on a periodical basis.
On the other hand, the image processing device has a sleep function aimed at electric power-saving. Even when the connection with the server is established, the image processing device enters a deep sleep mode if a predetermined condition is met. Once entering the deep sleep mode, the image processing device stops a function to communicate with the server on the periodical basis. The periodic communication with the server is not established, and the connection between the image processing device and the server may be terminated. In order to avoid this, even when the image processing device enters the deep sleep mode, it is required to put the power state of the image processing device back to an original normal mode at the predetermined time intervals to establish the periodic communication with the server.
The number of servers with which the image processing device establishes the constant connection is not always one. It is general to have the image processing device establishing the constant connections with the multiple servers on Internet to use a variety of cloud services. It is assumed that the image processing device establishes the constant connections with the multiple servers. In this case, the image processing device is required to establish a periodic communication with each server. The time interval between the periodic communications is different for each server. The image processing device, therefore, is often back to normal mode for the periodic communication with each server even soon after entering deep sleep mode. The conventional image processing devices are not allowed to obtain a full power saving effect.